<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
  <div id="app">
    <input v-focus="10"/>
  </div>
  <script src="./vue.js"></script>
  <script>
    Vue.directive('focus',{
      inserted(el,binding){
        /* console.log(el)
        console.log(binding) */
        // el.focus();
        el.style.background="red"
      }
    })
    const vm = new Vue({
      el: '#app'
    })
  </script>
</body>
</html>